I’ve had a number of BMW 5 Series (rear wheel drive) over the years which, out of the hundreds of cars that I’ve driven over the last 40+ years, are the closest to perfection that a car gets. I never noticed any issues in rain, but I once got stuck in a hotel car park after snowfall and had to stay the night! After that I avoided driving them when there was snow and took our AWD car instead which, in the same conditions, didn’t miss a beat even though, in every other respect, and in all other weather conditions, it was inferior to the 5 Series!